Rock And Rovers

Scientists are studying Ontario limestone to learn about extraterrestrial life

- Nicole Schmidt

Red lake, a small municipality northwest of Thunder Bay, is one of the most isolated tourist spots in Ontario. Each year, hundreds of wealthy visitors, mostly American, make the trek north to the region’s cluster of lakes to catch prize-worthy pike, trout, and walleye. One early morning last August, Stefan Lalonde, a scientist who had just flown in from France, joined the fishermen among the towering pine trees. Armed with a drill, a magnet, and a small bottle of hydrochloric acid, he had one particular prize in mind: rocks. Those rocks could eventually lead other scientists to extraterrestrial life.

Lalonde, who studied geomicrobiology at the University of Alberta and now works with the European Institute for Marine Studies, weaved his rented motorboat through the lake. Approximately thirty kilometres away from the town’s main dock, he found what he was looking for, just above the surface of the water. At first, the limestone seemed unexceptional: rigid and grey. But when Lalonde placed a single drop of acid on the rock, it reacted with the carbon dioxide inside and fizzed up like a baking-soda-and-vinegar volcano. With a small pick and hammer, he chiselled off samples of the rock, some of which he would transport back to his lab in Brest, France, where they would be cut, crushed, and analyzed to understand Earth’s early biosphere. Astronomers could then use that information to predict what kinds of planets can support life and then search the universe to find them.